A great variety of climbing chocks are known. Perhaps the most basic form of climbing chock is a simple wedge which is used, in a variety of sizes, to provide a support point for a climber. While the wedge has been quite successful, there are a number of situations in which the regularly shaped wedge with its flat sides does not provide as much security as may be desired. The wedge tends to provide a point contact on an irregular surface, which may allow the wedge to shift or slip.
A variation of the climbing wedge is the climbing nut, such as that shown in U.S. Pat. No. 3,948,485 to Chouinard et al. This climbing chock features a number of flat sides with provisions for a sling to be passed through the center of the climbing chock. Again, there are many instances when this device will result in point contact, and will not provide the required degree of support.
Chocks with irregular surfaces are disclosed in U.S. Pat. No. 4,422,607 to Vallance, U.S. Pat. No. 4,083,521 to Greiner II, and U.S. Pat. No. 4,044,976 and U.S. Pat. No. 3,957,237, both to Campbell.
As is evident from the drawings illustrating the use of the various climbing chocks in the above-identified patents, specific shaped chocks are suitable for a particular type of flaw, crevice, or crack, however, the configuration of the chocks do not provide a single style chock which may be used in a wide variety of rock configurations.